The B'Ita Achishena scenario requires that appointed people act in certain ways at appointed times. Hence, it is utterly important to study these appointed times, as well as the required actions. The Talmudic dictum that warns against computing end-times does not apply to B'Ita Achishena. It does apply to the B'Ita end-times, about which I will therefore not write more than I just did.
The proper way to interpret the above is as follows. Moshiach can come any day in case Am Yisrael does national Teshuva. In absence of such Teshuva, B'Ita Achishena applies, as long as it is intact. Using other language, Moshiach ben Yosef will redeem Israel, if he does not die. We will end up in the B'Ita scenario only if we should Chas v'Shalom fail to maintain B'Ita Achishena.
Again, the process of Geula in B'Ita Achishena is not automatic. The GR"A merited being the appointed person to set B'Ita Achishena in motion. In the same vein, keeping things on track depends on appointed people doing the right things at the right times. In a sense all of Israel is appointed. All can contribute to softening the process of Geula that is unfolding, or the opposite, G-d forbid. Yet, there are special tasks for special people. With the help of Heaven, I will relate to an important case in point in the next couple of posts.
הנצנים נראו בארץ עת הזמיר הגיע וקול התור נשמע בארצנו - הכוונה על יעודים, מועדים ומיועדים, הנצנים הם היעודים היינו עקבות משיחא. עת הזמיר הגיע, הם המועדים, היינו הקצין והפקידות. וקול התור נשמע הם המיועדים, היינו השליחים המיוחדים. וכולם כלולים ביעודו של משיח הראשון(קול התור ב:א:לח)
P.S. Regarding the identity of Yovel years (and various other relevant matters), see this book.
נז